Just about a month ago, the disease-geek world was riveted by news of the “Indian superbug“: common bacteria carrying a newly recognized gene that confers profound multi-drug resistance, and that was linked to travel between Europe and South Asia, especially for medical tourism.
The gene, which directs production of an enzyme called NDM-1 for short, was briefly Bug of the Week, the spur for alarmist headlines in every Internet echo chamber and the target of denunciations by Indian politicians, who vilified the discovery as a Western “pharma conspiracy” spurred by envy of lucrative medical tourism.
And then, just as quickly as it popped into public consciousness, NDM-1 slid back under the news-radar horizon.
Or so it seemed. Researchers though remain deeply concerned about NDM-1, along with a wider array of dire resistance factors of which it has suddenly become the best-known. This week, I’m at ICAAC (the annual Interscience Conference on Antimicrobial Agents and Chemotherapy), an enormous 12,000-person meeting focused on infectious diseases and the drugs to treat them, and talk of NDM-1 is everywhere.
The news is not good. This new resistance factor has been found so far in the United States, Canada, Belgium, the Netherlands, Austria, France, Germany, Oman, Kenya, Australia, Hong Kong and Japan. Most of the isolates, the bacterial samples in which it has been identified, are susceptible to only one or two remaining antibiotics. One was susceptible to none.
“These resistant bugs,” Dr. Patrice Nordmann, a professor of clinical microbiology at the South-Paris Medical School, said in a briefing here, “have already spread all over the world.”
A brief recap:
NDM-1 was first spotted in 2008, in a 59-year-old man of South Asian origin who lived in Sweden. He was hospitalized on a visit home to New Delhi, had surgery, recovered, went back to Sweden and was hospitalized there again. At that point, physicians recognized that he had a urinary tract infection that was unusually drug-resistant. The infection was caused by a common bacterium, Klebsiella pneumoniae, but the Klebsiella possessed an unusual and worrisome ability to disable carbapenems, a class of drugs given for very resistant infections. They named the enzyme and the gene directing its production for the place where the man had apparently acquired it: New Delhi metallo-beta-lactamase, and blaNDM.
In 2009, the United Kingdom’s public-health agency sent out an alert saying the same resistance mechanism was appearing there and increasing rapidly, going from unknown in 2007 to 18 instances in the first half of 2009, most of them in people who had gone to India for medical care or had frequent family travel back and forth. In June this year, the US Centers for Disease Control and Prevention put out a bulletin about NDM-1’s first US appearance, in three patients in three different states (California, Massachusetts and Illinois), again with ties to South Asian medical care.